Strawberry plant named &#39;ucd royal royce&#39;

ABSTRACT

‘UCD Royal Royce’ is a day-neutral strawberry cultivar of garden strawberry that provides high yields and produces fewer runners that many high-yielding day-neutral cultivars.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. patent applicationSer. No. 15/932,994, filed Jun. 7, 2018.

Genus and species: The strawberry cultivar of this invention isbotanically identified as Fragaria x ananassa Duchesne.

Variety denomination: The variety denomination is ‘UCD Royal Royce’.

BACKGROUND OF THE INVENTION

This invention relates to a new and distinct day-neutral strawberrycultivar designated as ‘UCD Royal Royce’, which originated from a crossperformed in the winter of 2008 between proprietary germplasm parents03C114P003 (unpatented) and 04C009P005 (unpatented). Seeds of the crosswere harvested from greenhouse-grown plants in the spring of 2008 andgerminated in June 2008. Seedlings were transplanted to a greenhouse inJuly 2008 and transplanted to the field in October 2008. ‘UCD RoyalRoyce’ was selected and clones were first harvested in 2009. ‘UCD RoyalRoyce’ has been asexually propagated since 2009.

The plant of this selection was originally designated ‘08C123P001’ andlater called ‘16DN009’ or ‘UC9’ for evaluation in field trials.

BRIEF SUMMARY OF THE INVENTION

‘UCD Royal Royce’ is a day-neutral (ever-bearing) strawberry cultivarselected for increased marketable fruit yield, extended shelf-life anddecreased runner (stolon) production. ‘UCD Royal Royce’ consistentlyproduces more marketable fruit per hectare, particularly during thefirst six to seventh months of an eight or nine-month harvest season,compared to San Andreas (U.S. Plant Pat. No. 19,975), ‘Monterey’ (U.S.Plant Pat. No. 19,767) or ‘Cabrillo’ (U.S. Plant Pat. No. 27,830); andhas fewer stolons (runners) than ‘Monterey’ or ‘Cabrillo’. ‘UCD RoyalRoyce’ also delivers yield earlier than cultivar ‘UCD Moxie’ (U.S. plantpatent application filed of even date under attorney docket number069516-1131471-231000US), whereas the cumulative marketable fruit yieldof ‘UCD Moxie’ surpasses that of ‘UCD Royal Royce’ late in the season.

‘UCD Royal Royce’ was genotyped with a 35,000-SNP array (Hardigan et.al., Plant Genome 11:180049, 2018). The variety has a unique DNA profilecompared to ‘Cabrillo’, ‘Monterey’, ‘UCD Moxie’, and ‘UCD Valiant’ (U.S.plant patent application filed of even date under attorney docket number069516-1131474-232000US). The pairwise genetic distances between ‘UCDRoyal Royce’ and ‘UCD Valiant’, ‘UCD Moxie’, ‘Cabrillo’, and ‘Monterey’are estimated to be 0.270, 0.167, 0.259, and 0.302, respectively basedon the 35,000-SNP genotype analysis.

‘UCD Royal Royce’ is maintained by annual asexual propagation by stolonsin Winters, Calif.

BRIEF DESCRIPTION OF THE DRAWINGS

The colors in the photograph are depicted as nearly true as isreasonably possible to obtain in color reproductions of this type.

FIG. 1 shows fruit of ‘UCD Royal Royce’ in cross-section.

FIG. 2 illustrates color of the fruit.

FIG. 3 depicts general flowering and fruiting characteristics of ‘UCDRoyal Royce’.

FIG. 4 shows representative fruit trusses of the plant.

FIG. 5 shows representative flowers of the plant.

FIG. 6 shows representative leaves of the plant.

FIG. 7 depicts plant habit.

DETAILED DESCRIPTION OF THE INVENTION Fruit Production

‘UCD Royal Royce’ and comparison cultivars were asexually propagated inhigh-elevation nurseries in Dorris and Mcdoel, Calif. for field testingin 2015-2016, 2016-2017, and 2017-2018. Clones were harvested accordingto commercial planting schedules, which were calibrated by the number ofchill hours required for optimum production in Santa Maria andPrunedale, Calif.

Cultivar testing in small-plot yield trials was performed as follows.Test day-neutral cultivars and comparison cultivars were field tested inOso Flaco (Santa Maria, Calif.) and Prunedale, Calif. in 2015-2016.Fruit was harvested once or twice per week over the spring and summergrowing season: Mar. 16 to Aug. 18, 2016 in Santa Maria (31 harvests)and Apr. 2 to Aug. 27, 2016 in Prunedale (30 harvests). ‘UCD RoyalRoyce’ was selected on the basis of fruit appearance, size, shelf-life,and cumulative marketable fruit yield for a second year (2016-17) ofreplicated testing in Santa Maria and Prunedale (Tables 1-2). Fruit washarvested once or twice per week over the growing season: Mar. 13 toAug. 21, 2017 in Santa Maria (25 harvests) and Apr. 3 to Sep. 1, 2017 inPrunedale (44 harvests in Prunedale). To highlight differences amongcultivars, the yield data were displayed in three ways: (a) per plantyields for individual harvests for each location×year combination for‘UCD Royal Royce’, ‘Monterey’, ‘San Andreas’, and ‘Cabrillo’; (b) perplant cumulative marketable yields for ‘UCD Royal Royce’, ‘Monterey’,‘San Andreas’, and ‘Cabrillo’; and (c) per plant cumulative marketableyields tested in both years and locations. Entry ranks were highlyconsistent and the best and worst performing cultivars were virtuallyidentical over locations and years.

Table 1 shows marketable yield (g/plant) for ‘UCD Royal Royce’ comparedto that for ‘Monterey’, ‘San Andreas’, and ‘Cabrillo’ tested insmall-plot yield trials in Santa Maria, Calif. and Prunedale, Calif. in2015-16 and 2016-17.

Table 2 shows the range in increase in yield compared to ‘Monterey’,‘San Andreas’, and ‘Cabrillo’ for the small-plot yield trials.

TABLE 1 Least-square means for cumulative marketable yield tested insmall-plot yield trials in Santa Maria, CA and Prunedale, CA in2015-2016 and 2016-2017 Yield across Locations and Santa Maria PrunedaleYears Cultivar 2015-16 2016-17 2015-16 2016-17 (g/plant) UCD Royal Royce2,016 2,329 1,750 2,632 2,183 Cabrillo 1,617 2,073 1,362 2,299 1,838Monterey 1,115 1,324 1,077 1,722 1,310 San Andreas 1,229 1,096 1,0481,569 1,236

TABLE 2 Least-square means for cumulative marketable yield (g/plant)across years and locations tested in the small-plot yield trials inSanta Maria and Prunedale. The ranges for yield increases overcomparison cultivars were estimated from least square means forindividual environments (see, Table 1). (Percent Marketable Fruit =(Cumulative Marketable Fruit Yield)/(Cumulative Total Fruit Yield) YieldIncrease Yield Yield Percent Range Increase Increase Yield MarketableOver San Range Over Range Over Cultivar (g/plant) Fruit Andreas MontereyCabrillo UCD Royal Royce 2,183 87-88 64-112% 53-81% 12-28% Cabrillo1,838 86-87 Monterey 1,310 79-82 San Andreas 1,236 76-84

The cumulative marketable fruit yields of ‘UCD Royal Royce’ weresignificantly greater than ‘Cabrillo’ (p<0.0078), ‘Monterey’ (p<0.0001),and ‘San Andreas’ (p<0.0001) across years and locations (Table 1). Theper plant yields of ‘UCD Royal Royce’ were 12 to 112% greater than‘Cabrillo’, ‘Monterey’, and ‘San Andreas’ (Table 2). The mean fruit sizefor ‘UCD Royal Royce’ (29.7 g/fruit) was not significantly differentfrom ‘Cabrillo’ (30.0 g/fruit; p=0.78) or Monterey (28.4 g/fruit;p=0.23), but was significantly greater than ‘San Andreas’ (26.7 g/fruit;p=0.007).

The marketable fruit percentages for ‘UCD Royal Royce’ and ‘Cabrillo’were comparable (86-88%) and superior to ‘Monterey’ and ‘San Andreas’(76 to 84%) (Table 2).

Significantly less runner production was observed in ‘UCD Royal Royce’compared to the other high yielding cultivars tested in small-plot yieldtrials. Runner production differences among cultivars could not beabsolutely quantified because growers trimmed runners to prevent thediversion of energy away from fruit production; however, it is estimatedbased on observation that runner production was reduced by at least 50%for ‘UCD Royal Royce’ compared to runner production by ‘San Andreas’,‘Monterey’, and ‘Cabrillo’. This was confirmed in large-plot yieldtrials described below.

‘UCD Royal Royce’ was selected, with other test varieties, for advancedtesting in large-plot yield trials (150 plants/plot) with fivecommercial growers in 2017-18. The selection criteria were: highcumulative marketable yields, high marketable fruit percentages,resistance to bruising and deterioration with harvest, handling, andstorage, fruit appearance, and reduced runner production in coastalproduction environments. The production systems for large-plot yieldtrials were diverse and included: low-input organic (Santa Maria,Calif.), low-input fumigated (Salinas, Calif.), and high-input fumigated(Oso Flaco, Calif., Prunedale, Calif. and Moss Landing, Calif.). Fruitwas harvested from February 2 to October 5 in Oso Flaco (52 harvests),April 3 to October 4 in Santa Maria (53 harvests), April 12 to October 6in Prunedale (48 harvests), May 7 to October 8 in Moss Landing (45harvests), and March 9 to October 12 in Salinas (36 harvests). Theresidual for statistical analyses was the entry×location interactionmean square.

TABLE 3 Least square means for cumulative marketable fruit yield(cartons/acre) for ‘UCD Royal Royce’, ‘Monterey’, and ‘Cabrillo’ grownin unreplicated large-plot (150 plant) yield trials in five locations in2017-18, where a carton = eight clamshells and eight clamshells/carton ×one pound/clamshell = eight pounds/carton. Santa Oso Mossing AcrossCultivar Salinas Maria Flaco Prunedale Landing Locations UCD Royal 8,72911,042 16,837 15,069 10,603 12,456 Royce Cabrillo 5,201  6,892 17,56914,057  9,465 10,637 Monterey NA  7,891 14,731 11,940 10,257 10,274

TABLE 4 Least square means for fruit weight (g/fruit) for ‘UCD RoyalRoyce’, ‘Monterey’, and ‘Cabrillo’ grown in unreplicated large-plot (150plant) yield trials in in five locations in 2017-18, where fruit weight= (weight of fruit per clamshell)/(number of fruit per clamshell). SantaOso Mossing Across Cultivar Salinas Maria Flaco Prunedale LandingLocations UCD Royal 25.0 21.8 28.5 28.6 34.1 27.6 Royce Cabrillo 26.121.9 28.0 27.5 34.0 27.5 Monterey NA 21.6 29.4 27.9 33.8 27.8

TABLE 5 Statistical significance (Pr > F) of differences between leastsquare means for cumulative fruit yield (cartons/acres) and fruit weight(g/fruit) for ‘UCD Royal Royce’, ‘Monterey’, and ‘Cabrillo’ tested inunreplicated large-plot (150 plant) yield trials in five locations in2017-18. Yield Fruit Weight (g/fruit) Difference Difference Comparison(carton/acre) Pr > F (g/fruit) Pr > F UCD Royal Royce- 2,182 0.0392−0.22 0.6631 Monterey OCD Royal Royce-Cabrillo 1,820 0.0610  0.11 0.8133

The mean cumulative marketable yields ‘UCD Royal Royce’ was 12,456cartons/acre=99,648 pounds/acre across production systems and locations(Table 3). Reduced runner production was observed for ‘UCD Royal Royce’across trials. ‘UCD Royal Royce’ was the highest yielding cultivarthrough August, 2018 compared to ‘Monterey’, ‘Cabrillo’, and two othertest cultivars (data not shown), and second highest yielding cultivarthrough October, 2018 compared to ‘Monterey’, ‘Cabrillo’ (Table 3) andtwo other test cultivars (data not shown). The cumulative marketablefruit yields of (Table 3) were significantly greater than ‘Monterey’(p=0.039) and ‘Cabrillo’ (p=0.061) (Table 5). ‘UCD Royal Royce’ produced1,820 cartons/acre (11,144 pounds/acre) more than ‘Cabrillo’ and 2,182cartons/acre (17,464 pounds/acre) more than ‘Monterey’ (Tables 3 & 5).‘UCD Royal Royce’ fruit weights were not significantly different from‘Monterey’ (p=0.49) or ‘Cabrillo’ (p=0.46) (Tables 4 & 5).

To assess the quality of freshly harvested fruit, firmness (gramsforce), total soluble solids (SS) concentration, and titratable acid(TA) concentrations were measured from samples of fruit harvested onthree dates from each location in 2017-18 (Tables 6-7). Harvest dateswere one month apart with one replication per harvest date, 10sub-samples per replication for firmness, and three subsamples perreplication for SS and TA. Firmness was quantified with a hand-heldpenetrometer measuring the grams of force needed to puncture the fruit.SS and TA concentrations were quantified with benchtop instruments. TheSS to TA ratio provides a relative measure of sweetness. To assessshelf-life, fruit weight (g/clamshell), SS, brightness (ordinal scalewith 1=excellent to 5=unmarketable), liquid leakage (g/clamshell), andmold incidence (%) were quantified from samples of fruit harvested ontwo dates from each location with fruit stored under standard 4° C.conditions for 0, 7, 14, and 21 days (Table 8). Harvest dates were onemonth apart with one replication per harvest date.

TABLE 6 Least-square means (LSMs) for firmness, soluble solidsconcentration (SS), and titratable acid concentration (TA) for ‘UCDRoyal Royce’, ‘Monterey’, and ‘Cabrillo’ grown in five locations in2017-18. LSMs were estimated from three harvest dates per location, onebiological replication per harvest date, 10 sub-samples per harvest datefor firmness, and three sub-samples per harvest for SS and TA. TitrableFirmness Acids Cultivar (g force) SS (%) (g/100 ml) SS/TA UCD RoyalRoyce 430.94 7.94 0.84  9.48 Cabrillo 359.61 8.05 0.77 10.50 Monterey294.55 8.71 0.77 11.48

TABLE 7 Statistical significance (Pr > F) of differences between leastsquare means for SS, TA, and SS/TA for ‘UCD Royal Royce’, ‘Monterey’,and ‘Cabrillo’ tested in unreplicated large-plot yield trials in fivelocations in 2017-18. Soluble Solids Titratable Acids SS/TAConcentration (SS) Concentration (TA) Least Least Square Least SquareSquare Mean Difference Mean Difference Mean Comparison (%) Pr > F (g/100ml) Pr > F Difference Pr > F UCD Royal −0.77 0.0405 0.07 0.0090 −2.00<0.0001 Royce- Monterey UCD Royal −0.11 0.7808 0.06 0.0231 −1.02  0.0185Royce- Cabrillo

TABLE 8 Least-square means (LSMs) for fruit weight (g/clamshell),soluble solids concentration (SS), fruit brightness, liquid leakage, andmold formation for ‘UCD Royal Royce’, ‘Monterey’, and ‘Cabrillo’ grownin four locations 2017-18 and stored for zero to 21 days postharvest.LSMs were estimated from two harvest dates per location Days Post-Soluble Liquid Harvest Weight Solids Leakage Mold Cultivar Storage(g/clamshell) (%) Brightness (g) (%) UCD Royal  0 555.7 7.3 1.0 0.0 0.0Royce Cabrillo  0 555.4 7.5 1.3 0.0 0.0 Monterey  0 572.0 9.2 1.2 0.00.0 UCD Royal  7 538.0 7.6 2.1 0.2 0.0 Royce Cabrillo  7 538.7 7.4 2.00.2 0.0 Monterey  7 556.3 9.1 1.8 0.0 0.0 UCD Royal 14 523.0 7.5 3.4 0.01.0 Royce Cabrillo 14 522.9 7.3 3.3 0.8 1.2 Monterey 14 542.3 9.5 3.00.0 0.5 UCD Royal 21 508.6 7.0 4.1 0.8 12.7  Royce Cabrillo 21 504.4 7.34.3 35.8  36.7  Monterey 21 526.4 8.7 3.8 0.2 11.8 

‘UCD Royal Royce’ produced fruit meeting or exceeding industry standardsfor mass-production cultivars (Tables 6-8). The fruit was firm,withstood the rigors of harvest, packing, and storage, and maintainedacceptable fruit quality and appearance for over two weeks of storage.‘UCD Royal Royce’ produced significantly firmer fruit than either‘Cabrillo’ (p<0.0001) or ‘Monterey’ (p<0.0001). ‘UCD Royal Royce’additionally had significantly lower SS concentration than ‘Monterey’(p<0.0001), but was not significantly different compared to ‘Cabrillo’(p=0.78). The SS/TA ration for ‘UCD Royal Royce’ was significantly lowerthan ‘Monterey’ (p<0.0001) and ‘Cabrillo’ (p<0.019) .

‘UCD Royal Royce’ maintained adequate marketability and visual appealover 14 days of post-harvest storage, the industry standard (Table 8),as did ‘Cabrillo’ and ‘Monterey’. The marketability of fruit stored for21 days post-harvest was inadequate for all three cultivars. Fruitweight and brightness significantly decreased as post-harvest storagetime increased (Table 8). The fruit weight decreases were notsignificantly different among cultivars. Cultivar×post-harvest storagetime interactions were only statistically significant for liquid leakageand mold formation, with ‘Cabrillo’ deteriorating more than ‘UCD RoyalRoyce’ and ‘Monterey’ (Table 8).

Disease Resistance Evaluation

‘UCD Royal Royce’ and additional cultivars were screened for resistanceto Fusarium wilt, Verticillium wilt, Macrophomina, and Phytophthoracrown rot in Davis, Calif. field experiments between 2015 and 2018.These included 2015-16 and 2016-17 Fusarium wilt screening experimentswith 480 to 960 entries, a 2015-16 Macrophomina experiment with 960entries, 2016-17 and 2017-18 Verticillium wilt experiments with 480 to960 entries, and a 2017-18 Phytophthora crown rot experiment with 480entries. Entries were arranged in randomized complete blocks experimentdesigns with four single-plant replications per entry. The 2015-16experiments were planted in virgin soil in Davis, Calif. The 2016-17 and2017-18 experiments were planted in fumigated soils in Davis, Calif. Foreach experiment, plants were artificially inoculated with the respectivepathogen and phenotyped for disease symptoms on an ordinal scale, where1=highly resistant (symptomless), 2=resistant, 3=intermediate,4=susceptible, and 5=highly susceptible (dead). Within each experiment,plants were phenotyped at six different time points to study changes inthe phenotypic distributions and quantify the progression of diseasesymptoms over time.

‘UCD Royal Royce’ was susceptible to Fusarium wilt (4.5 on scale),moderately susceptible to Verticillium wilt (3.1 on scale), moderatelysusceptible to Phytophthora crown rot (3.3 on scale), and susceptible toMacrophomina (5.0 on scale).

BOTANICAL DESCRIPTION

The following botanical descriptors are characteristic of ‘UCD RoyalRoyce’. The descriptors were collected from two different sites in May2017 in Santa Maria, Calif. The characteristics of ‘UCD Royal Royce’ mayvary in detail, depending upon environmental factors and cultureconditions.

-   Growth habitat: Semi-upright.-   Density of foliage: Medium.-   Vigor: Medium.-   Position of inflorescence in relation to foliage: Same level.-   Number of stolons: Few.-   Stolon, anthocyanin coloration: Medium.-   Stolon, density of pubescence: Sparse.-   Leaf size: Medium.-   Leaf, color of upper side: Medium green.-   Leaf blistering: Absent.-   Leaf glossiness: Medium glossy.-   Leaf variegation: Absent.-   Terminal leaflet, length in relation to width: Moderately longer in    length compared to width.-   Terminal leaflet, shape of base: Obtuse.-   Terminal leaflet, margin: Serrate to crenate.-   Terminal leaflet, shape in cross section: Concave.-   Petiole, length: Medium.-   Petiole, Attitude of hairs: Horizontal.-   Stipule, anthocyanin coloration: Absent or very weak.-   Inflorescence, number of flowers: Many.-   Pedicel, attitude of hairs: Slightly outwards.-   Flower diameter: Medium.-   Flower, arrangement of petals: Touching.-   Flower, size of calyx in relation to corolla: Larger.-   Flower stamen: Present.-   Petal, length in relation to width: Equal.-   Petal, color of upper side: White.-   Fruit, length in relation to width: Moderately longer.-   Fruit size: Large.-   Fruit shape: Conical.-   Fruit, difference in shape of terminal and other fruits: None or    very slight.-   Fruit color: Medium red.-   Fruit, evenness of color: Even or very slightly uneven.-   Fruit glossiness: Medium.-   Fruit, evenness of surface: Even or very slightly uneven.-   Fruit, width of band without achenes: Absent or very narrow.-   Fruit, positions of achenes: Below surface.-   Fruit, position of calyx attachment: Inserted.-   Fruit, attitude of sepals: Upwards.-   Fruit, diameter of calyx in relation to fruit diameter: Slightly    larger.-   Fruit, adherence of calyx: Strong.-   Fruit firmness: Very firm.-   Fruit, color of flesh (excluding core): Light red.-   Fruit, color of core: Light red.-   Fruit cavity: Absent or small.-   Time of beginning of flowering: Medium.-   Time of beginning of fruit ripening: Medium.-   Type of bearing: Day neutral.

What is claimed is:
 1. A new and distinct cultivar of strawberry planthaving the characteristics substantially as described and illustratedherein.